Biochemical changes in stored potato tubers with different rest periods

Abstract

Summary The protein changes in the eyes and the parenchyma of stored potato tubers of cvs. Baca and Bem, having different rest periods and the effects of storage temperature and isopropyl phenylcarbamates on the protein were studied. The amount of proteins decreased after harvest, increased during the winter months and decreased again during sprout growth. Among the soluble proteins the participation of a high-molecular protein fraction decreased and protein with lower molecular weights simultaneously increased during the rest period. During sprout growth the amounts of high-molecular proteins and of polypeptides increased in the eyes and were dominant in soluble proteins from the sprouts. The changes were more evident in the tubers of cv. Bem with their shorter rest period and more intense sprout growth, than in the tubers of cv. Baca. Isopropyl phenylcarbamates inhibited the displacement of nitrogenous compounds from the internal to the external part of the tubers, prevented changes in the soluble protein fractions in the stored tubers and inhibited protein synthesis in the eyes. Low storage temperature induced dissociation of proteins, lowered participation of the proteins in the total nitrogen, and reduced protein synthesis.